docs: def check_path(path, credentials=None):
      """
      Check that specified output path does not already exist
  
      The ValueError message will suggest calling with overwrite=True;
      this function is expected to be called from the various output methods
      that accept an 'overwrite' keyword argument.
      """
      from thunder.readers import get_file_reader
      reader = get_file_reader(path)(credentials=credentials)
      existing = reader.list(path, directories=True)
      if existing:
          raise ValueError('Path %s appears to already exist. Specify a new directory, '
                           'or call with overwrite=True to overwrite.' % path)